μ(1,2,3)=(1+2+3)/3=2
μ(1,2,4)=(1+2+4)/3=2.3
μ(1,2,5)=(1+2+5)/3=2.7
μ(1,2,6)=(1+2+6)/3=3
μ(2,3,4)=(2+3+4)/3=3
μ(2,3,5)=(2+3+5)/3=3.3
μ(2,3,6)=(2+3+6)/3=3.7
μ(3,4,5)=(3+4+5)/3=4
μ(3,4,6)=(3+4+6)/3=4.3
μ(4,5,6)=(4+5+6)/3=5
f(2)=f(2.3)=f(2.7)=f(3.3)=f(3.7)=f(4)=f(4.3)=f(5)=1/10
f(3)=2/10
E(x)=∑xf(x)=1/10(2+2.3+2.7+3.3+3.7+4+4.3+5)+2/10×3=2.73+0.6=3.33
σ2=∑x2f−(∑xf)2=1/10(4+5.29+7.29+10.89+13.69+16+18.49+25)+2/10×9−3.332=11.865−11=0.865
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